Rheological characterisation of selected food hydrocolloids by traditional and simplified techniques

Empirical and fundamental rheological properties of six food hydrocolloids (carboxymethylcellulose, tara gum, guar gum, locust bean gum, xanthan gum and sodium alginate), as influenced by concentration, were evaluated and correlated. Furthermore, the possibility to estimate the empirical and fundamental parameters by using data coming from a very simple and inexpensive rotational viscometer prototype, was investigated. The prototype was build in laboratory and its simplicity consist of the capability to directly measure a voltage, correlated with the absorbed current, instead of a derived torque and rotation speed measurements of the cylinder probe. Fundamental rheological measurements were performed by using a controlled stress-strain rheometer, while a back extrusion test was performed in order to evaluate the empirical properties.